In real-time voice network transmission, in order to improve voice quality, a real-time voice transmission system needs to select a suitable voice compression algorithm and a transmission method according to indexes, such as an actual application network capability and transmission bandwidth, delay, complexity, and voice quality, so as to improve the cost performance of voice signal transmission as much as possible.
In numerous voice codecs, G.711 is widely applied in an actual application due to advantages, such as a simple algorithm, strong robust, and short delay. The international telecommunication union telecommunication standardization sector (ITU Telecommunication Standardization Sector, ITU-T) proposes two extended voice encoder standards, G.711.1 and G.711.0, based on the narrowband voice encoder G.711. In G.711.1, broadband extension is performed based on the G.711 narrowband to implement broadband voice quality. In G.711.0, lossless compression is performed on a G.711 code stream to reduce transmission bandwidth by about 50%, thereby improving transmission quality of a voice signal during network congestion.
During implementation of the present invention, the inventor finds that, G.711.1 and G.711.0 in the prior art cannot reduce the transmission bandwidth and improve the voice quality at the same time.